Biochemical tool

ABSTRACT

It is an object of the present disclosure to provide a biochemical tool capable of satisfactorily reducing absorption of a biochemical substance to a surface contacting a sample of the biochemical substance. A biochemical tool configured to contact a sample of a biochemical substance includes a part configured to contact the sample of the biochemical substance, the part being made of a resin composition containing at least one cycloolefin polymer selected from the group consisting of a copolymer of a cycloolefin and a chain olefin, a ring-opened polymer of a cycloolefin, and a hydrogenated product of a ring-opened polymer of a cycloolefin, and an antioxidant, the resin composition including 0.01 parts by mass or more and 0.7 parts by mass or less of the antioxidant relative to 100 parts by mass of the cycloolefin polymer.

TECHNICAL FIELD

The present disclosure relates to a biochemical tool configured tocontact a sample of a biochemical substance.

BACKGROUND

Cycloolefin resins are excellent in melt processability, fluidity,thermal shrinkage, print characteristics, and the like, and thus havebeen used in various applications. In addition to these characteristics,their excellent transparency, chemical resistance, moisture resistance,mechanical properties, and the like have expanded applications ofcycloolefin resins to other fields, such as biochemical tools.

In the meantime, in one application etc. of biochemical tools, moldedarticles made of resin compositions are employed as storage containers,measuring devices, and the like for handling biochemical substances suchas proteins and nucleic acids. Upon handling a sample or the likecontaining a biochemical substance in a relatively low concentration,absorption of the biochemical substance to a surface of the moldedarticle may be problematic. Specifically, during operations such asstorage, transportations, measurements, dilutions, and analyses ofsamples, absorption of biochemical substances in the samples to thesurfaces of biochemical tools may cause various problems, such asmeasurement errors, reduced sensitivities, loss of the content, andcomplete loss of a trace sample.

Thus, efforts have been made for developing a technique to reduceabsorption of a biochemical substance to a surface brought contact witha sample, of a biochemical tool made of a material containing acycloolefin resin.

Specifically, for example, PTL-1 has proposed to reduce absorption of abiochemical substance to a surface of a molded article by treating thesurface of the molded article by a surface treatment for a moldedarticle including the steps of subjecting the surface of the moldedarticle made of a material containing a cycloolefin resin to plasmadischarge, and bringing the surface of the molded article into contact astrong acid.

In addition, PTL-2 has proposed to reduce absorption of a biochemicalsubstance to the surface of a molded article by a surface treatmentincluding the step of irradiating the surface of the molded article madeof a material containing a cycloolefin resin with vacuum-ultravioletlight to thereby form a self-assembled monomolecular film on the surfacebeing irradiated.

CITATION LIST Patent Literature

PTL-1: JP2010-241984A

PTL-2: WO 2012/161048A1

SUMMARY Technical Problem

However, there still remains room for improvements in such conventionalbiochemical tools configured from molded articles, in terms of reductionin absorption of a biochemical substance to surfaces contacting a samplecontaining the biochemical substance (biochemical substance sample).

Accordingly, it is an object of the present disclosure to provide abiochemical tool capable of satisfactorily reducing absorption of abiochemical substance to a surface contacting a sample of thebiochemical substance.

The present inventor has conducted extensive studies to solve theaforementioned problem. The present inventor then has found that abiochemical tool having a part that is configured to contact a sample ofa biochemical substance and is made from a predetermined resincomposition can satisfactorily reduce absorption of the biochemicalsubstance to a surface contacting the sample of the biochemicalsubstance, and has completed the present disclosure.

Solution to Problem

Specifically, the present disclosure aims to advantageously solve theabove-mentioned problem, and the biochemical tool of the presentdisclosure is a biochemical tool configured to contact a sample of abiochemical substance, comprising:

a part configured to contact the sample of the biochemical substance,the part being made of a resin composition containing at least onecycloolefin polymer selected from the group consisting of a copolymer ofa cycloolefin and a chain olefin, a ring-opened polymer of acycloolefin, and a hydrogenated product of a ring-opened polymer of acycloolefin, and an antioxidant, the resin composition comprising 0.01parts by mass or more and 0.7 parts by mass or less of the antioxidantrelative to 100 parts by mass of the cycloolefin polymer. In cases wherethe part configured to contact the sample of the biochemical substancein the biochemical tool is formed of the resin composition containing acertain cycloolefin polymer and an antioxidant in a certain amount asdescribed above, absorption of the biochemical substance can besatisfactorily reduced.

In the present embodiment, the content of the antioxidant in the resincomposition can be measured by the procedure described in the EXAMPLESsection of the present specification.

In the biochemical tool of the present disclosure, the antioxidantpreferably includes a hindered phenolic antioxidant. In cases where theantioxidant contains the hindered phenolic antioxidant, absorption ofthe biochemical substance to a surface contacting the sample of thebiochemical substance can be reduced even more satisfactorily.

Further, in the biochemical tool of the present disclosure, the contactangle to water of the part configured to contact the sample of thebiochemical substance is preferably 85° or more. In cases where thecontact angle to water of the part configured to contact the sample ofthe biochemical substance is equal to or greater than theabove-mentioned value, absorption of the biochemical substance to asurface contacting the sample of the biochemical substance can befurther satisfactorily reduced.

In the present embodiment, the contact angle to water of the partconfigured to contact the sample of the biochemical substance can bemeasured by the procedure described in the EXAMPLES section of thepresent specification.

Advantageous Effect

According to the present disclosure, a biochemical tool is providedwhich can satisfactorily reduce absorption of a biochemical substance toa surface contacting a sample of the biochemical substance.

BRIEF DESCRIPTION OF THE DRAWING

In the accompanying drawing:

FIG. 1 are graphs indicating the relationships of DNA concentrationsversus detected peak areas of SEC-UV of dilution series of a DNAstandard sample prepared in Examples 2 and 5 and Comparative Examples 9and 10.

DETAILED DESCRIPTION

Hereinafter, an embodiment of the present disclosure will be describedin detail.

(Biochemical Tool)

The biochemical tool of the present disclosure is a biochemical toolconfigured to contact a sample of a biochemical substance, which has apart configured to contact the sample of the biochemical substance andoptionally a part configured not to contact the sample of thebiochemical substance. The biochemical tool is characterized in that thepart configured to contact the sample of the biochemical substance ismade of a resin composition containing a certain cycloolefin polymer andan antioxidant in a certain amount. The biochemical tool of the presentdisclosure can satisfactorily reduce absorption of a biochemicalsubstance to a surface contacting a sample of the biochemical substance.

Specific examples of the biochemical tool of the present disclosureinclude instruments such as those described on pages 13 to 30 in BioExperiments from Beginning (published from SANKYO SHUPPAN Co., Ltd.)(May 2002), and more specifically are beakers, flasks, petri dishes,pipettes, syringes, centrifuge tubes, needles, tubes, Eppendorf tips,titer plates, micro channels, filters, test cells, storage containers,and containers for analytical instruments. The biochemical tool of thepresent disclosure, however, is not limited to the above tools, butincludes any tools that may contact a sample containing a biochemicalsubstance.

<Sample of Biochemical Substance>

A sample of a biochemical substance that contacts the biochemical toolof the present disclosure is not specifically limited as long as it is asample including a biochemical substance, but it generally refers to afluid sample including a biochemical substance dissolved or dispersed inany medium. A sample of a biochemical substance may include any othercomponents other than the biochemical substance.

Examples of the biochemical substance include proteins, enzymes,antibodies, polypeptides, oligopeptides, amino acids, nucleic acids,lipids, polysaccharides, oligosaccharides, amino sugars, microorganisms,and viruses. It is to be noted that nucleic acids may include bothribonucleic acids (RNAs) and deoxyribonucleic acids (DNAs). Thebiochemical substance is not limited to substances obtained frombiological materials by techniques such as extraction, and also includessubstances chemically synthesized outside organisms. Particularlypreferred biochemical substances are nucleic acids. In cases where abiochemical substance includes a nucleic acid, absorption of abiochemical substance to a surface contacting a sample of thebiochemical substance in the biochemical tool can be reduced moresatisfactorily.

The solvent is not specifically limited as long as it can dissolve ordisperse the biochemical substance, and water is used, for example.

The concentration of the biochemical substance in the sample of thebiochemical substance is not specifically limited, but the concentrationis preferably 10000 mg/L or less, more preferably 1000 mg/L or less, andeven more preferably 100 mg/L or less. In cases where the concentrationof a biochemical substance in a sample of the biochemical substance is10000 mg/L or less, absorption of the biochemical substance to a surfacecontacting the sample of the biochemical substance in the biochemicaltool can be reduced further satisfactorily.

<Contacting Part>

The part configured to contact a sample of a biochemical substance(hereinafter may be merely referred to as the “contacting part”) of thebiochemical tool of the present disclosure is made of a resincomposition containing a certain cycloolefin polymer and an antioxidantin a certain amount.

Here, the contacting part is not specifically limited as long as it is apart that may contact a sample of a biochemical substance in thebiochemical tool, and may have any shape, area, and volume. Specificexamples of the contacting part include an inner wall of a container,such as a beaker, a flask, and a storage container; and inner and outerwalls of a measurement tool, such as a pipette and an Eppendorf tip.

The physical properties of the contacting part are not specificallylimited, but the contact angle to water of the contacting part ispreferably 85° or and more, more preferably 87° or more. In cases wherethe contact angle to water of the contacting part is 85° or more,absorption of a biochemical substance to a surface contacting a sampleof the biochemical substance in the biochemical tool can be reduced moresatisfactorily. The contact angle to water of the contacting part ispreferably 100° or less, and more preferably 95° or less.

The contacting part may be subjected to any of a wide variety of surfacetreatments for controlling the above-mentioned contact angle to water orfor other purposes. The surface treatments include, but are notspecifically limited to, physicochemical treatments such as plasmadischarge, corona discharge, flame treatment, ultraviolet irradiation,electron beam irradiation, and exposure to radiation; chemicaltreatments such as exposure to chemical agents, steaming, and surfacegrafting; and mechanical treatments such as sandblasting and embossing.

[Resin Composition]

The resin composition configuring the contacting part contains a certaincycloolefin polymer and an antioxidant in a certain amount, and mayfurther include an optional additional component.

—Cycloolefin Polymer—

The cycloolefin polymer includes at least one cycloolefin polymerselected from the group consisting of a copolymer of a cycloolefin and achain olefin, a ring-opened polymer of a cycloolefin, and a hydrogenatedproduct of a ring-opened polymer of a cycloolefin. In view of increasingthe strength of a resin composition and a contacting part made of theresin composition, a hydrogenated of having a ring-opened polymer of acycloolefin is preferably used as the cycloolefin polymer.

—Copolymer of Cycloolefin and Chain Olefin

A copolymer of a cycloolefin and a chain olefin is typically a polymerobtained by addition copolymerization of the cycloolefin and the chainolefin.

Specific examples of the cycloolefin include as follows:

monocyclic cycloolefins such as cyclopentene, cyclohexene, cyclooctene,cyclopentadiene, and 1,3-cyclohexadiene;

bicyclic cycloolefins such as bicyclo [2.2.1] hepta-2-ene (common name:norbornene, hereinafter may be abbreviated as “NB”), 5-methyl-bicyclo[2.2.1] hepta-2-ene, 5,5-dimethyl-bicyclo [2.2.1] hepta-2-ene,5-ethyl-bicyclo [2.2.1] hepta-2-ene, 5-butyl-bicyclo [2.2.1]hepta-2-ene, 5-ethylidene-bicyclo [2.2.1] hepta-2-ene, 5-hexyl-bicyclo[2.2.1] hepta-2-ene, 5-octyl-bicyclo [2.2.1] hept-2-ene,5-octadecyl-bicyclo [2.2.1] hept-2-ene, 5-methylidene-bicyclo [2.2.1]hept-2-ene, 5-vinyl-bicyclo [2.2.1] hept-2-ene, and 5-propenyl-bicyclo[2.2.1] hept-2-ene;

tricyclic cycloolefins such as tricyclo [5.2.1.0^(2,6)] deca-3,8-diene(common name: dicyclopentadiene, hereinafter may be abbreviated as“DCP”), tricyclo [5.2.1.0^(2,6)] deca-3-ene, tricyclo [6.2.1.0^(2,7)]undeca-3,9-diene, tricyclo [6.2.1.0^(2,7)] undeca-4,9-diene, tricyclo[6.2.1.0^(2,7)] undeca-9-ene, 5-cyclopentyl-bicyclo [2.2.1] hepta-2-ene,5-cyclohexyl-bicyclo [2.2.1] hepta-2-ene, 5-cyclohexenylbicyclo [2.2.1]hepta-2-ene, and 5-phenyl-bicyclo [2.2.1] hepta-2-ene;

tetracyclic cycloolefins such as tetracyclo [6.2.1.1^(3,6).0^(2,7)]dodeca-4-ene (also referred to simply as “tetracyclododecene”,hereinafter may be abbreviated as “TCD”); 9-methyl tetracyclo[6.2.1.1^(3,6).0^(2,7)] dodeca-4-ene, 9-ethyl tetracyclo[6.2.1.1^(3,6).0^(2,7)] dodeca-4-ene (hereinafter may be abbreviated as“ETD”), 9-methylidene tetracyclo [6.2.1.1^(3,6).0^(2,7)] dodeca-4-ene,9-ethylidene tetracyclo [6.2.1.1^(3,6).0^(2,7)] dodeca-4-ene,9-vinyltetracyclo [6.2.1.1^(3,6).0^(2,7)] dodeca-4-ene,9-propenyl-tetracyclo [6.2.1.1^(3,6).0^(2,7)] dodeca-4-ene, tetracyclo[9.2.1.0^(2,10).0^(3,8)] tetradeca-3,5,7,12-tetraene (also referred toas 1,4-methano-1,4,4a,9a-tetrahydrofluorene, hereinafter may beabbreviated as “MTF”), and tetracyclo [10.2.1.0^(2,11).0^(4,9)]pentadeca-4,6,8,13-tetraene (also referred to as1,4-methano-1,4,4a,9,9a,10-hexahydro anthracene);

pentacyclic cycloolefins and cycloolefins having 6 or more rings, suchas 9-cyclopentyl-tetracyclo [6.2.1.1^(3,6).0^(2,7)] dodeca-4-ene,9-cyclohexyl-tetracyclo [6.2.1.1^(3,6).0^(2,7)] dodeca-4-ene,9-cyclohexenyl-tetracyclo [6.2.1.1^(3,6).0^(2,7)] dodeca-4-ene,pentacyclo [6.6.1.1^(3,6.)0^(2,7).0^(9,14)]-4-hexadecene, pentacyclo[6.5.1.1^(3,6).0^(2,7).0^(9,13)]-4-pentadecene, pentacyclo[7.4.0.0^(2,7).1^(3,6).1^(10,13)]-4-pentadecene,9-phenyl-cyclopentyl-tetracyclo [6.2.1.1^(3,6).0^(2,7)] dodeca-4-ene,heptacyclo[8.7.0.1^(2,9).1^(4,7).1^(11,17).0^(3,8).0^(12,16)]-5-eicosene, andheptacyclo[8.7.0.1^(2,9).0^(3,8).1^(4,7).0^(12,17).1^(13,16)]-14-eicosene.14-eicosene.

These cycloolefins may be used alone or in combination of two or more.

Specific examples of the chain olefin is not specifically limited aslong as they are copolymerizable with the above-mentioned cycloolefin,and include linear or branched olefins having a carbon number of 2 to20, such as ethylene, propylene, butene, pentene, hexene, butadiene,pentadiene, and hexadiene, for example.

The method of preparing the copolymer of a cycloolefin and a chainolefin is not specifically limited, and well-known techniques forcopolymerizing the cycloolefin and the chain olefin as described abovecan be used.

—Ring-Opened Polymer of Cycloolefin—

A ring-opened polymer of a cycloolefin is a polymer prepared byring-opening polymerization of one or more cycloolefins.

As the cycloolefin, the same cycloolefins as the above-mentionedcycloolefins used for preparing the copolymer of a cycloolefin and achain olefin can be used.

The method of preparing the ring-opened polymer of a cycloolefin is notspecifically limited, and well-known techniques for ring-openingpolymerization of the above-mentioned cycloolefin such as metathesispolymerization, for example, can be used.

—Hydrogenated Product of Ring-Opened Polymer of CYCLOOLEFIN

A hydrogenated product of a ring-opened polymer of a cycloolefin isprepared by a hydrogenation of a ring-opened polymer of the cycloolefinas described above.

The method of hydrogenating the ring-opened polymer of the cycloolefinis not specifically limited, and well-known techniques can be used, forexample, a technique in which a well-known hydrogenation catalystcontaining a transition metal, such as nickel and palladium, is added toa solution of the ring-opened polymer of the cycloolefin, to therebyhydrogenate carbon-carbon double bonds in the ring-opened polymer.

The hydrogenation ratio is preferably 90% or more, more preferably 95%or more, even more preferably 99% or more, and still more preferably99.6% or more.

The hydrogenation ratio can be measured by the procedure described inthe EXAMPLES section of the present specification.

—Physical Properties of Cycloolefin Polymer—

The physical properties of the above-mentioned cycloolefin polymer arenot specifically limited, but the glass-transition temperature of thecycloolefin polymer is preferably 60° C. or higher, more preferably 100°C. or higher, and even more preferably 130° C. or higher, for example.In cases where the glass-transition temperature of the cycloolefinpolymer of 60° C. or higher, absorption of the biochemical substance toa surface contacting the sample of the biochemical substance in thebiochemical tool can be reduced further satisfactorily.

It is to be noted that, in the present disclosure, the glass-transitiontemperature of the cycloolefin polymer can be measured in accordancewith JIS K6911.

—Content of Cycloolefin Polymer—

The content of the cycloolefin polymer in the resin composition ispreferably 70% by mass or more, more preferably 80% by mass or more, andeven more preferably 90% by mass or more. In cases where the content ofthe cycloolefin polymer of 70% by weight or more, absorption of thebiochemical substance to a surface contacting the sample of thebiochemical substance in the biochemical tool can be reduced furthersatisfactorily.

—Antioxidant—

As the antioxidant, for example, primary antioxidants such as a hinderedphenolic antioxidant and an amine-based antioxidant, and secondaryantioxidants such as a phosphoric antioxidant and a sulfuricantioxidant, can be used.

Specific examples of the hindered phenolic antioxidant include alkylsubstituted hindered phenolic antioxidants such aspentaerythritol-tetrakis [3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], 3,9-bis{2-[3-(3-t-butyl-4-hydroxy-5-methylphenyl)propionyloxy]-1,1-dimethylethyl} 2,4,8,10-tetraoxaspiro[5,5] undecan,octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl) propionate,1,6-hexanediol-bis [3-(3,5-di-t-butyl-4-hydroxyphenyl) propionate],1,3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene,2,6-di-t-butyl-4-methylphenol, 2,6-di-t-butyl-4-ethyl phenol,2,6-diphenyl-4-octadecyloxyphenol, stearyl(3,5-di-t-butyl-4-hydroxyphenyl) propionate, thiodiethylene glycolbis[(3,5-di-t-butyl-4-hydroxyphenyl) propionate], 4,4′-thiobis(6-t-butyl-m-cresol), 2,2′-methylene bis(4-methyl-6-t-butyl-6-butylphenol), 2,2′-methylene bis(4-ethyl-6-t-butylphenol), bis [3,3-bis (4-hydroxy-3-t-butylphenyl)butylic acid] glycol ester, 4,4′-butylidenebis (6-t-butyl-m-cresol),2,2′-ethylidene bis (4,6-di-t-butylphenol), 2,2′-ethylidenebis(4-s-butyl-6-t-butylphenol), 1,1,3-tris(2-methyl-4-hydroxy-5-t-butylphenyl) butane, bis[2-t-butyl-4-methyl-6-(2-hydroxy-3-t-butyl-5-methylbenzyl) phenyl]terephthalate, 1,3,5-tris (2,6-dimethyl-3-hydroxy-4-t-butylbenzyl)isocyanurate, 1,3,5-tris(3,5-di-t-butyl-4-hydroxybenzyl)-2,4,6-trimethylbenzene, 1,3,5-tris[(3,5-di-t-butyl-4-hydroxyphenyl) propionyloxyethyl] isocyanurate, andtetrakis [methylene-3-(3,5-di-t-butyl)-4-hydroxyphenyl) propionate];alkoxy-substituted hindered phenolic antioxidants such as3,5-di-t-butyl-4-hydroxyanisole; and hindered phenolic antioxidantscontaining triazine groups such as6-(4-hydroxy-3,5-di-t-butylanilino)-2,4-bisoctylthio-1,3,5-triazine,4-bisoctylthio-1,3,5-triazine, and2-octylthio-4,6-bis-(3,5-di-t-butyl-4-oxyanilino)-1,3,5-triazine.

Specific examples of the amine-based antioxidant include hinderedamine-based compounds, such as 2,2,6,6-tetramethyl-4-piperidyl stearate,1,2,2,6,6-pentamethyl-4-piperidyl stearate,1-hydroxy-2,2,6,6-tetrammethyl piperidinol,2,2,6,6-tetramethyl-4-piperidyl benzoate,bis(2,2,6,6-tetramethyl-4-piperidyl) cebacate,bis(1,2,2,6,6-pentamethyl-4-piperidyl) cebacate,bis(2,2,6,6-tetramethyl-4-piperidyl)-di(tridecyl)-1,2,3,4-butanetetracarboxylate,bis(1,2,6,6,6-pentamethyl-4-piperidyl)-di(tridecyl)-1,2,3,4-butanetetracarboxylate,1-(2-hydroxyethyl)-2,2,6,6-tetramethyl-4-piperidinol/diethyl succinatepolycondensate, 1,6-bis (2,2,6,6-tetramethyl-4-piperidylamino)hexane/dibromoethane polycondensate,1,6-bis(2,2,6,6-tetramethyl-4-piperidylamino)hexane/2,4-dichloro-6-morpholino-s-triazine polycondensate, 1,6-bis(2,2,6,6-tetramethyl-4-piperidylamino)hexane/2,4-dichloro-6-tert-octylamino-s-triazine polycondensate,1,5,8,12-tetrakis [2,4-bis (N-butyl-N-(2,2,6,6-tetramethyl-4-piperidyl)amino)-s-triazine-6-yl]-1,5,8,12-tetraazadodecane, and 1,5,8,12-tetrakis[2,4-bis(N-butyl-N-(1,2,2,6,6-pentamethyl-4-piperidyl)amino)-s-triazine-6-yl]-1,5,8,12-tetraazadodecane; and dialkylhydroxylamine-based compounds such as diethylhy droxylamine, dioctylhydroxylamine, didodecyl hydroxylamine, and dioctadecyl hydroxylamine.

Specific examples of the phosphoric antioxidant includebis-(2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphite,tris(2,4-di-t-butylphenyl phosphite), tetrakis(2,4-di-t-butyl-5-methylphenyl)-4,4′-biphenylene diphosphonite,bis-(2,6-dicumylphenyl) pentaerythritol diphosphate, 2,2-methylenebis(4,6-di-t-butylphenyl) octyl phosphite, bis (2,4-di-t-butylphenyl)pentaerythritol-di-phosphite, bis (2,6-di-t-butyl-4-methoxycarbonylethyl-phenyl) pentaerythritol diphosphite; and bis(2,6-di-t-butyl-4-octadecyl oxycarbonylethyl-phenyl) pentaerythritoldiphosphite.

Specific examples of the sulfuric antioxidant include dilauryl 3,3-thiodipropionate, dimyristyl 3,3′-thio dipropionate, distearyl 3,3-thiodipropionate, laurylstearyl 3,3-thio dipropionate,pentaerythritol-tetrakis (β-lauryl-thio-propionate), and3,9-bis(2-dodecylthioethyl)-2,4,8,10-tetraoxaspiro[5,5] undecane.

From the viewpoint of satisfactorily reducing absorption of abiochemical substance to the contacting part, hindered phenolicantioxidants are preferably used as the antioxidant, and of these,pentaerythritol tetrakis [3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate]is more preferably used.

One of the above antioxidant can be used alone or in combination of twoor more.

The content of the antioxidant in the resin composition needs to be 0.01parts by mass or more, and is preferably 0.05 parts by mass or more,more preferably 0.09 parts by mass or more, and needs to be 0.7 parts bymass or less, and is preferably 0.6 parts by mass or less, morepreferably 0.5 parts by mass or less, relative to 100 parts by mass ofthe above-mentioned cycloolefin polymer. In cases where the content ofthe antioxidant is 0.01 part by mass or more and 0.7 part by mass orless relative to 100 parts by mass of the cycloolefin polymer,absorption of the biochemical substance to a surface contacting thesample of the biochemical substance in the biochemical tool can besatisfactorily reduced.

—Other Components—

In addition to the cycloolefin polymer and the antioxidant describedabove, the resin composition may contain an optional component to theextent that desired effects are achieved. Specifically, examples of theoptional component include additives that can be used in uponpreparation of cycloolefin polymers such as a chain transfer agent, apolymerization regulator, a polymerization reaction retarder, and areactive fluidizing agent; polymers other than the cycloolefin polymersuch as a rubbery polymer and a thermoplastic elastomer; organic orinorganic fillers; inorganic particulates; additives for resins such asa flame retardant, an ultraviolet absorber, a weathering stabilizer, anantistatic agent, a slipping agent, a metal soap, an antifogging agent,and a plasticizer; oils such as a natural oil and a synthetic oil; amold releasing agent; a fluorescent whitening agent; a dye; a pigment; acolorant; an antimicrobial agent; a deodorant; and a deodorizer.

It is to be noted that commonly-used compounds can be used as anoptional component, such as compounds described in JP2009-242568A,compounds described in JP2010-100683A, and compounds described inJP5613981B, for example.

—Method of Preparing Resin Composition

The method of preparing the resin composition is not specificallylimited and any of well-known techniques may be used. For example, theresin composition can be prepared by melt-kneading a certain cycloolefinpolymer and an antioxidant in a certain amount, as well as an optionalcomponent(s), as described above, in a single screw extruder or atwin-screw extruder.

The temperature upon the melt-kneading is not specifically limited, butis preferably 180° C. or higher, more preferably 200° C. or higher, evenmore preferably 220° C. or higher, and preferably 350° C. or lower, morepreferably 320° C. or lower, and even more preferably 300° C. or lower.

<Part Configured not to Contact Sample of Biochemical Substance>

The biochemical tool of the present disclosure optionally has a partconfigured not to contact a biochemical substance. Specific examples ofthe part configured not to contact the biochemical substance includeouter walls of containers such as beakers, flasks, etc., and grips ofmeasurement tools such as pipettes, etc.

In the biochemical tool of the present disclosure, the part configurednot to contact a sample of a biochemical substance may be formed of theabove-mentioned resin composition containing a certain cycloolefinpolymer and an antioxidant in a certain amount, or may be formed of aresin composition other than the above-mentioned resin composition, or amaterial other than the resin composition, such as a metal or a ceramic.

<Method of Manufacturing Biochemical Tool>

The method of manufacturing the biochemical tool is not specificallylimited as long as the biochemical tool to be manufactured has acontacting part as described above, and a method of forming theabove-mentioned resin composition into the form of the biochemical toolor the like is used, for example. Alternatively, a method of coating acontacting part of a biochemical tool made of the above-mentioned resincomposition, with a material different from the resin composition, mayalso be used.

The method of forming the above-mentioned resin composition is notspecifically limited, and any well-known techniques may be used.Specifically, techniques such as injection molding, injectioncompression molding, gas-assisted injection molding, extrusion molding,multi-layer extrusion molding, rotational molding, hot press molding,blow molding, foam molding, and molding by a 3D printer can be cited.

The conditions upon molding of the resin composition are notparticularly limited, but in the case of injection molding, thetemperature of the resin composition is preferably 180° C. or higher,more preferably 200° C. or higher, even more preferably 220° C. orhigher, and preferably 350° C. or lower, more preferably 320° C. orlower, and even more preferably 300° C. or lower, for example.

Examples of the coating method include well-known techniques, such asdipping; coating by a brush or the like; spraying; and coating by acoater such as a roll coater, a bar coater, or a knife coater.

EXAMPLES

In the following, the present disclosure will described referring toexamples. However, the present disclosure is not limited to theseexamples. It should be noted that “parts” and “%” in these examples arerepresented by mass unless otherwise stated.

In each of Production Examples, Examples, and Comparative Examples, thehydrogenation ratio and the glass-transition temperature of acycloolefin polymer; the content of an antioxidant in a resincomposition; the contact angle of a contacting part to water; theDNA-absorption ratio; and the linearity of the dilution series data wasmeasured, calculated, or evaluated in the following procedures.

<Hydrogenation Ratio>

The hydrogenation ratio of each ring-opened polymer of a cycloolefin anda hydrogenated product of that polymer prepared in Production Examples 1to 3 were determined by obtaining ¹H-NMR spectra in heavy chloroform asa solvent, to thereby calculate the percentage of unsaturated bonds thatdisappeared in hydrogenation reaction, out of the total unsaturatedbonds that were present in the ring-opened polymer of the cycloolefins.

<Glass-Transition Temperature>

The glass-transition temperature of a cycloolefin polymer prepared ineach of Production Examples was measured using a differential scanningcalorimeter (manufactured by Nanotechnology Corporation under theproduct name of DSC6220S11) in accordance with JIS K 6911.

<Content of Antioxidant in Resin Composition>

An Eppendorf tube container fabricated in each of Examples andComparative Examples (hereinafter, sometimes referred to simply as“container”) was processed into a sheet in 0.1 mm thick by a heatpressing machine at 200° C. in a nitrogen atmosphere. The IR spectrum ofthis sheet was obtained by FT-IR transmission to determine the ratio ofthe peaks of the antioxidant to the peaks of the cycloolefin polymer,and the content (parts by mass) of the antioxidant relative to 100 partsby mass of the cycloolefin polymer in the resin composition wasdetermined from a calibration curve. It should be noted that an IRspectrometer manufactured by Thermo Scientific Co., Ltd. under theproduct name of AVATAR360 was used.

<Contact Angle of Contacting Part to Water>

A static contact angle determined by a curve fitting technique using agoniometer manufactured by Kyowa Interface Science Co., Ltd. under theproduct name of Drop Master 300 was used as the contact angle to waterof a part configured to contact a sample of a biochemical substance of acontainer prepared in each of Examples and Comparative Examples.

<DNA Absorption Ratio>

The DNA absorption ratio was calculated as the percentage of a DNAabsorbed to containers when a solution of the DNA as a sample of abiochemical substance was transferred from a container to another, bythe following procedure:

1) A dilution series in three stages having DNA concentrations of 1000mg/L, 100 mg/L, and 10 mg/L were prepared using a DNA standard sample(deoxyribonucleic acid (DNA) solution for quantitative analysis, NMIJCRM 6205-a, DNA chain length: 600 bps) as a biochemical sample.2) Of the solutions of the dilution series, the DNA solution in anarbitrary concentration was dispensed into a container to be evaluated.3) The container was tapped about 20 times to splash the DNA solutiononto the inner wall surface of the container, thereby the DNA wasbrought into contact with the inner wall surface of the container.4) The DNA solution remaining on the inner wall surface of the containerwas spun down in a tabletop centrifuge.5) Leaving the amount to be analyzed, a part of the DNA solution in thecontainer was transferred to an unused container to be evaluated. Theremainder of the DNA solution to be analyzed was transferred and used asa sample after one transfer operation.6) The operations of 3) to 5) above were repeated 9 times on the DNAsolution transferred to the unused container, to obtain samples after2^(nd) to 10^(th) transfer operations.7) The sample before the transfer operations of the DNA solution used in2) above and the samples after the 1^(st) to 10^(th) transfer operationswere transferred to analysis tubes and were analyzed by SEC-UV to obtaina peak area (A₀) derived from the amount of the DNA in the sample beforethe transfer operations and respective peak areas (A₁ to A₁₀) derivedfrom the amounts of remaining DNA in the DNA solution after the 1^(st)to 10^(th) container transfer operations. Thereafter, the respective DNAabsorption ratios (B₁ to B₁₀) (%) after 1^(st) to 10^(th) containertransfer operations were calculated by the following equation.

B _(n)={(A ₀ −A _(n)}×100 (n is the order of container transferoperation)

An evaluated container having a smaller DNA absorption ratio (B_(n))more satisfactorily reduced absorption of the biochemical substance to asurface contacting the sample of the biochemical substance.

The conditions for SEC-UV measurements were as follows:

-   -   HPLC: LC-10Avp System (manufactured by Shimadzu Corporation)    -   Column: Yarra-2000 (Phenomenex)    -   Elute: 0.1 mol/L tris-HCl (pH 8.1)    -   Detection: UV detector (260 nm)

<Linearity of Dilution Series Data>

A dilution series in five stages having DNA concentrations of 10 μg/L,50 μg/L, 100 μg/L, 500 μg/L, and 1000 μg/L were prepared in containersto be evaluated using a DNA standard sample (deoxyribonucleic acid (DNA)solution for quantitative analysis, NMIJ CRM 6205-a, DNA chain length:600 bps) as a biochemical sample. For each solution of the dilutionseries, the container was tapped about 20 times to splash the DNAsolution onto the inner wall surface of the container, thereby the DNAwas brought into contact with the inner wall surface of the container.The DNA solution was spun down by the tabletop centrifuge. The dilutionseries was analyzed by SEC-UV, and a scatter plot of the dilution seriesdata with the obtained peak area on the vertical axis and the DNAconcentration on the horizontal axis were generated to evaluate thelinearity of the dilution series data. An evaluated container having ahigher linearity of the obtained dilution series data absorbed a smalleramount of the biochemical substance, indicating that absorption of thebiochemical substance to the surfaces contacting the samples of thebiochemical substance was prevented more satisfactorily.

It is to be noted that the measurement conditions of the SEC-UV were thesame as the measurement conditions of the DNA absorption ratio describedabove.

(Production Example 1) Production of Hydrogenated Product A ofRing-Opened Polymer of Cycloolefins

In a reactor, 0.82 parts of 1-hexene, 0.15 parts of dibutyl ether, and0.30 parts of triisobutylaluminum were charged to 500 parts ofcyclohexane that had been dehydrated in a nitrogen atmosphere, and wasstirred at room temperature (25° C.). Thereafter, while being maintainedat 45° C., 76 parts of tricyclo [4.3.0.1^(2,5)] deca-3,7-diene (DCP), 70parts of tetracyclo [4.4.0.1^(2,5).1^(7,10)] dodeca-3-ene (TCD), 54parts of tetracyclo [7.4.0.0^(2,7).1^(10,13)]tetradeca-2,4,6,11-tetraene (MTF), and 80 parts of tungsten hexachloride(0.7% toluene solution) were continuously added over 2 hourssimultaneously to cause polymerization. Thereafter, 1.06 parts of butylglycidyl ether and 0.52 parts of isopropyl alcohol were added to thepolymerization solution to deactivate the polymerization catalyst, tothereby terminate the polymerization reaction. The resulting reactionsolution containing a ring-opened polymer was analyzed by gaschromatography, and the polymerization conversion rate of the respectivemonomers was determined to be determined to be 99.5%.

Subsequently, 270 parts of cyclohexane was added to 100 parts of theresultant reaction solution containing the ring-opened polymer, and 5parts of a nickel catalyst carried on diatomaceous earth (manufacturedby Nissan Gurdor Co., Ltd. under the product name of G-96D; nickelcarrying ratio: 58%) was added as a hydrogenation catalyst. The reactionsolution was heated to a temperature of 200° C. while being stirred andpressurized to 5 MPa with hydrogen, to cause a reaction for 8 hours toobtain a reaction solution containing a hydrogenated product ofDCP/TCD/MTF ring-opened copolymer. The hydrogenation catalyst wasfiltered off, and cyclohexane as the solvent other volatile componentswere removed with a cylindrical evaporator (manufactured by HitachiLtd.) at temperatures of 270° C. under a pressure of 1 kPa or less. Thehydrogenated product in a molten state was then extruded from anextruder into strands, cooled, and pelletized to obtain pellets. Thepelletized hydrogenated product of the ring-opened copolymer(hydrogenated product A of the ring-opened polymer of the cycloolefins)had a hydrogenation ratio of 99.8% and a glass-transition temperature of136° C.

(Production Example 2)Production of Hydrogenated Product B ofRing-Opened Polymer of Cycloolefins

To a reactor in a nitrogen atmosphere at room temperature (25° C.), 250parts of dehydrated cyclohexane was added, and 0.84 parts of 1-hexene,0.06 parts of dibutyl ether, and 0.11 parts of triisobutyl aluminum wereadded and mixed. Thereafter, while the mixture was maintained at 45° C.,85 parts of DCP, 15 parts of 8-ethyl tetracyclo [4.4.0.1^(2,5).1^(7,10)]dodeca-3-ene (ETD), and 15 parts of tungsten hexachloride (0.7% toluene)were continuously added over 2 hours simultaneously to causepolymerization. The resultant reaction solution containing thering-opened polymer was analyzed by gas chromatography, and thepolymerization conversion rate of the respective monomers was determinedto be 100%.

The resultant polymerized reaction solution was transferred to apressure-resistant hydrogenation reactor, and 5 parts of a nickelcatalyst carried on diatomaceous earth (manufactured by Nissan GirdlerCatalyst Co., Ltd. under the product name of G-96D; nickel carryingratio: 58%) as a hydrogenation catalyst and 100 parts of cyclohexanewere added, and the polymerized reaction solution was reacted at 150° C.under a hydrogen pressure of 4.4 MPa for 8 hours. This reaction solutionwas pressure-filtered (Hunda filter, manufactured by Ishikawajima HarimaHeavy Industries, Ltd.) using diatomaceous earth (manufactured by ShowaChemical Industry Co., Ltd. under the product name of Radiolite #500) asa filtration bed under a pressure of 0.25 MPa to remove thehydrogenation catalyst from the reaction solution.

Subsequently, pellets of hydrogenated product of the ring-openedcopolymer (hydrogenated product B of the ring-opened polymer of thecycloolefins) were produced in the same manner as in Production Example1.

The pelletized hydrogenated product of the ring-opened copolymer had ahydrogenation ratio of 99.6% and a glass-transition temperature of 102°C.

(Production Example 3) Production of Hydrogenated Product C ofRing-Opened Polymer of Cycloolefins

A dry, nitrogen-substituted polymerization reactor was charged with 7parts of a monomer mixture of bicyclo[2.2.1]hepta-2-ene (norbornene,NB), DCP, and TCD (weight ratio: 38:31:31), 1600 parts of dehydratedcyclohexane, 3.5 parts of 1-hexene as a molecular weight regulator, 1.3parts of diisopropyl ether, 0.33 parts of isobutyl alcohol, 0.84 partsof triisobutyl aluminum, and 30 parts of a 0.66% solution of tungstenhexachloride in cyclohexane, and the solution was stirred at 55° C. for10 minutes. The reaction system was then kept at 55° C., and 93 parts ofa monomer mixture of the same composition as the above-mentioned monomermixture described above, and 72 parts of a 0.77% tungsten hexachloridecyclohexane solution were continuously dripped over 150 minutes whilethe solution was being stirring. The stirring was continued for 30minutes after the dripping ended, and 1.0 part of isopropyl alcohol wasadded to terminate the polymerization reaction. The polymerizationreaction solution was analyzed by gas chromatography, and the conversionratio of the monomers to the polymer was determined to be 100%.

Subsequently, 300 parts of the polymerization reaction solutioncontaining the above polymer was transferred to an autoclave equippedwith a stirrer, and 100 parts of cyclohexane and 2.0 parts of a nickelcatalyst carried on diatomaceous earth (manufactured by Nikko ChemicalCo., Ltd. under the product name of T8400RL; nickel carrying ratio: 58%)were added to the polymerization reaction solution. After the air insidethe autoclave was replaced with hydrogen, a reaction was carried out for6 hours at 170° C. under a hydrogen pressure of 4.9 MP.

The solution was filtered through a filter made of a stainless-steelwire mesh provided with diatomaceous earth (manufactured by ShowaChemical Industry Co., Ltd. under the product name of Radiolite #500) asa filtering aid, to thereby remove the catalyst from the solution. Theresulting reaction solution was poured into 8000 parts of isopropylalcohol that was being stirred to precipitate a hydride, which wascollected by filtration. The filtrate was washed with 500 parts ofacetone, and was then dried for 24 hours in a vacuum dryer set at0.13×10³ Pa or less and 65° C. to obtain a hydrogenated product of thering-opened copolymer.

Subsequently, pellets of hydrogenated product of the ring-openedcopolymer (hydrogenated product C of the ring-opened polymer of thecycloolefins) were produced in the same manner as in ProductionExample 1. The pelletized hydrogenated product of the ring-openedcopolymer had a hydrogenation ratio of 99.6% and a glass-transitiontemperature of 68° C.

(Production Example 4) Production of Copolymer D of Cycloolefin andChain Olefin

To a reactor charged with 258 L of cyclohexane, NB (120 kg) were addedat room temperature (25° C.) under a stream of nitrogen, and the mixturewas stirred for 5 minutes. Triisobutyl aluminum was then added so thatits concentration in the system was 1.0 mL/L. Subsequently, ethylene wasflowed at normal pressure while the mixture was being stirred, to createan ethylene atmosphere within the system. The autoclave was maintainedat an internal temperature of 70° C. and was pressurized with ethyleneso that the internal pressure was 6 kg/cm² at a gauge pressure. Afterstirring for 10 minutes, copolymerization of ethylene and NB wasinitiated by adding 0.4 L of a previously prepared toluene solutioncontaining isopropylidene (cyclopentadienyl) (indenyl) zirconiumdichloride and methyl alumoxane into the system. The catalystconcentrations of isopropylidene (cyclopentadienyl) (indenyl) zirconiumdichloride and methyl alumoxane were 0.018 mmol/L and 8.0 mmol/L,respectively, in the entire system.

During the polymerization, ethylene was continuously fed into the systemto keep the temperature at 70° C. and the internal pressure at 6 kg/cm²at the gauge pressure. After 60 minutes, the polymerization reaction wasterminated by adding isopropyl alcohol. After depressurization, thepolymer solution was taken out, and then the polymer solution wasbrought into contact an aqueous solution containing 5 L of concentratedhydrochloric acid added to 1 m³ of water, at a ratio of 1:1 with strongagitation to thereby transfer the catalyst residue to an aqueous phase.After the contacted mixed solution was allowed to stand, the aqueousphase was separated off and washed twice with water, to thereby purifyand separate the organic phase.

Thereafter, the purified and separated polymerization solution wasbrought into contact in acetone in a volume of 3-fold of thepolymerization solution to precipitate the copolymer, and the solid part(copolymer) was then collected by filtration and washed thoroughly withacetone. Further, in order to extract unreacted monomers present in thepolymer, the solid part was poured into acetone so that theconcentration was 40 kg/m³, and the unreacted monomers were thenextracted at 60° C. for 2 hours. After the extraction, the solid partwas collected by filtration, and the solid part was dried for 12 hoursat 130° C. under 350 mmHg in a nitrogen stream to obtain an ethylene-NBcopolymer (copolymer D of a cycloolefin and a chain olefin).

Subsequently, pellets of an ethylene-NB copolymer (copolymer D of thecycloolefin and the chain olefin) were obtained in the same manner as inProduction Example 1. The glass-transition temperature of the pelletizedethylene-NB copolymer was 138° C.

Example 1

In a blender, 100 parts of the hydrogenated product A of the ring-openedpolymer of the cycloolefins prepared in Production Example 1 and 0.01parts of pentaerythritol tetrakis [3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate] as an antioxidant were mixed. The mixture was then kneadedand extruded using a two-axis kneader provided with nitrogen-substitutedpoppers at a cylinder temperature of 290° C. to produce a pelletizedresin composition A-1.

Subsequently, the pelletized resin composition A-1 was injection moldedusing an injection molding machine ROBOSHOTα100B manufactured by FANUCCORPORATION under the conditions of a temperature of the resincomposition of 300° C. and a mold temperature of 100° C. to produceEppendorf tube containers with a volume of 1.5 ml. For the containers,the content of the antioxidant in the resin composition, the contactangle to water of the inner wall surface, which was the part configuredto contact the sample of the biochemical substance (contacting part) inthe Eppendorf tube container, and the DNA-absorption ratio were measuredor calculated. The results are summarized in Table 1.

Example 2

A resin composition A-2 was prepared in the same manner as in Example 1except that the amount of the antioxidant added was 0.1 parts. Containerwere then produced by injection molding in the same manner as in Example1, and the content of the antioxidant in the resin composition, thecontact angle to water of the contacting part, the DNA absorption ratio,and the linearity of the dilution series data was measured, calculated,or evaluated. The results are summarized in Table 1 and FIG. 1.

Example 3

A resin composition A-3 was prepared in the same manner as in Example 1except that the amount of the antioxidant added was 0.3 parts. Containerwere then produced by injection molding in the same manner as in Example1, and the content of the antioxidant in the resin composition, thecontact angle to water of the contacting part, and the DNA-absorptionratio were measured or calculated. The results are summarized in Table1.

Comparative Example 1

A resin composition A-4 was prepared in the same manner as in Example 1except that no antioxidant was added. Container were then produced byinjection molding in the same manner as in Example 1, and the content ofthe antioxidant in the resin composition, the contact angle to water ofthe contacting part, and the DNA-absorption ratio were measured orcalculated. The results are summarized in Table 1.

Comparative Example 2

A resin composition A-5 was prepared in the same manner as in Example 1except that the amount of the antioxidant added was 0.75 parts.Container were then produced by injection molding in the same manner asin Example 1, and the content of the antioxidant in the resincomposition, the contact angle to water of the contacting part, and theDNA-absorption ratio were measured or calculated. The results aresummarized in Table 1.

Example 4

In a blender, 100 parts of the hydrogenated product B of the ring-openedpolymer of the cycloolefins prepared in Preparation Example 2 and 0.01parts of pentaerythritol tetrakis [3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate] as an antioxidant were mixed, and the mixture was kneadedand extruded in a twin-screw kneader substituted with nitrogen at acylinder temperature of 285° C. to produce a pelletized resincomposition B-1.

Subsequently, the pelletized resin composition B-1 was injection moldedusing the injection molding machine ROBOSHOTα100B manufactured by FANUCCORPORATION under the conditions of a temperature of the resincomposition of 290° C. and a mold temperature of 80° C. to produceEppendorf tube containers with a volume of 1.5 ml. For the containers,the content of the antioxidant in the resin composition, the contactangle to water of the contacting part, and the DNA-absorption ratio weremeasured or calculated. The results are summarized in Table 1.

Example 5

A resin composition B-2 was prepared in the same manner as in Example 4except that the amount of the antioxidant added was 0.1 parts. Containerwere then produced by injection molding in the same manner as in Example4, and the content of the antioxidant in the resin composition, thecontact angle to water of the contacting part, the DNA absorption ratio,and the linearity of the dilution series data was measured, calculated,or evaluated. The results are summarized in Table 1 and FIG. 1.

Example 6

A resin composition B-3 was prepared in the same manner as in Example 4except that the amount of the antioxidant added was 0.5 parts. Containerwere then produced by injection molding in the same manner as in Example4, and the content of the antioxidant in the resin composition, thecontact angle to water of the contacting part, and the DNA-absorptionratio were measured or calculated. The results are summarized in Table1.

Comparative Example 3

A resin composition B-4 was prepared in the same manner as in Example 4except that no antioxidant was added. Container were then produced byinjection molding in the same manner as in Example 4, and the content ofthe antioxidant in the resin composition, the contact angle to water ofthe contacting part, and the DNA-absorption ratio were measured orcalculated. The results are summarized in Table 1.

Comparative Example 4

A resin composition B-5 was prepared in the same manner as in Example 4except that the amount of the antioxidant added was 0.75 parts.Container were then produced by injection molding in the same manner asin Example 4, and the content of the antioxidant in the resincomposition, the contact angle to water of the contacting part, and theDNA-absorption ratio were measured or calculated. The results aresummarized in Table 1.

Example 7

In a blender, 100 parts of the hydrogenated product C of the ring-openedpolymer of the cycloolefins prepared in Production Example 3 and 0.01parts of pentaerythritol tetrakis [3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate] as an antioxidant were mixed, and the mixture was kneadedand extruded in a twin-screw kneader substituted with nitrogen at acylinder temperature of 260° C. to produce a pelletized resincomposition C-1.

Subsequently, the pelletized resin composition C-1 was injection moldedusing the injection molding machine ROBOSHOTα100B manufactured by FANUCCORPORATION under the conditions of a temperature of the resincomposition of 250° C. and a mold temperature of 40° C. to produceEppendorf tube containers with a volume of 1.5 ml. For the containers,the content of the antioxidant in the resin composition, the contactangle to water of the contacting part, and the DNA-absorption ratio weremeasured or calculated. The results are summarized in Table 2.

Example 8

A resin composition C-2 was prepared in the same manner as in Example 7except that the amount of the antioxidant added was 0.1 parts. Containerwere then produced by injection molding in the same manner as in Example7, and the content of the antioxidant in the resin composition, thecontact angle to water of the contacting part, and the DNA-absorptionratio were measured or calculated. The results are summarized in Table2.

Example 9

A resin composition C-3 was prepared in the same manner as in Example 7except that the amount of the antioxidant added was 0.5 parts. Containerwere then produced by injection molding in the same manner as in Example7, and the content of the antioxidant in the resin composition, thecontact angle to water of the contacting part, and the DNA-absorptionratio were measured or calculated. The results are summarized in Table2.

Comparative Example 5

A resin composition C-4 was prepared in the same manner as in Example 7except that no antioxidant was added. Container were then produced byinjection molding in the same manner as in Example 7, and the content ofthe antioxidant in the resin composition, the contact angle to water ofthe contacting part, and the DNA-absorption ratio were measured orcalculated. The results are summarized in Table 2.

Comparative Example 6

A resin composition C-5 was prepared in the same manner as in Example 7except that the amount of the antioxidant added was 0.75 parts.Container were then produced by injection molding in the same manner asin Example 7, and the content of the antioxidant in the resincomposition, the contact angle to water of the contacting part, and theDNA-absorption ratio were measured or calculated. The results aresummarized in Table 2.

Example 10

In a blender, 100 parts of the copolymer D of the cycloolefin and thechain olefin prepared in Production Example 4 and 0.01 parts ofpentaerythritol tetrakis [3-(3,5-di-t-butyl-4-hydroxyphenyl) propionate]as an antioxidant were mixed, and the mixture was kneaded and extrudedusing a two-axis kneader provided with nitrogen-substituted poppers at acylinder temperature of 290° C. to produce a pelletized resincomposition D-1.

Subsequently, the pelletized resin composition D-1 was injection moldedusing the injection molding machine ROBOSHOTα100B manufactured by FANUCCORPORATION under the conditions of a temperature of the resincomposition of 300° C. and a mold temperature of 100° C. to produceEppendorf tube containers with a volume of 1.5 ml. For the containers,the content of the antioxidant in the resin composition, the contactangle to water of the contacting part, and the DNA-absorption ratio weremeasured or calculated. The results are summarized in Table 2.

Example 11

A resin composition D-2 was prepared in the same manner as in Example 10except that the amount of the antioxidant added was 0.1 parts. Containerwere then produced by injection molding in the same manner as in Example10, and the content of the antioxidant in the resin composition, thecontact angle to water of the contacting part, and the DNA-absorptionratio were measured or calculated. The results are summarized in Table2.

Example 12

A resin composition D-3 was prepared in the same manner as in Example 10except that the amount of the antioxidant added was 0.5 parts. Containerwere then produced by injection molding in the same manner as in Example10, and the content of the antioxidant in the resin composition, thecontact angle to water of the contacting part, and the DNA-absorptionratio were measured or calculated. The results are summarized in Table2.

Comparative Example 7

A resin composition D-4 was prepared in the same manner as in Example 10except that no antioxidant was added. Container were then produced byinjection molding in the same manner as in Example 10, and the contentof the antioxidant in the resin composition, the contact angle to waterof the contacting part, and the DNA-absorption ratio were measured orcalculated. The results are summarized in Table 2.

Comparative Example 8

A resin composition D-5 was prepared in the same manner as in Example 10except that the amount of the antioxidant added was 0.75 parts.Container were then produced by injection molding in the same manner asin Example 10, and the content of the antioxidant in the resincomposition, the contact angle to water of the contacting part, and theDNA-absorption ratio were measured or calculated. The results aresummarized in Table 2.

Comparative Example 9

Polypropylene (manufactured by Sumitomo Chemical Co., Ltd. under theproduct name of Excellen® AR244M, Excellen is a registered trademark inJapan, other countries, or both; melting point: 157° C. measured byISO3146) was injection molded using the injection molding machineROBOSHOTα100B manufactured by FANUC CORPORATION under the conditions ofa temperature of the resin composition of 240° C. and a mold temperatureof 70° C. to produce Eppendorf tube containers with a volume of 1.5 ml.For the containers, the contact angle to water of the contacting part,the DNA-absorption ratio, and the linearity of dilution series data weremeasured, calculated, or evaluated. The results are summarized in Table2 and FIG. 1.

Comparative Example 10

The contact angle to water of the contacting part, the DNA-absorptionratio, and the linearity of dilution series data were calculated orevaluated using a commercially available Eppendorf tube containers witha volume of 1.5 ml made of polypropylene (manufactured by CorningCorporation under the product name of Axygen Maximum Recovery Tube),which had been surface-treated to improve smoothness. The results aresummarized in Table 2 and FIG. 1.

TABLE 1 Comparative Comparative Example 1 Example 1 Example 2 Example 3Example 2 Resin Cycloolefinic Types Hydrogenated HydrogenatedHydrogenated Hydrogenated Hydrogenated composition polymer product A ofproduct A of product A of product A of product A of ring-openedring-opened ring-opened ring-opened ring-opened polymer of polymer ofpolymer of polymer of polymer of cycloolefins cycloolefins cycloolefinscycloolefins cycloolefins Production method Production ProductionProduction Production Production Example 1 Example 1 Example 1 Example 1Example 1 Glass-transition 136 136 136 136 136 temperature (° C.)Content 100 100 100 100 100 (parts by mass) Antioxidant Content 0 0.010.09 0.47 0.72 (parts by mass) Biochemical tool (Eppendorf tube Contactangle of 76 90 91 89 83 container) contacting part to water (°)Evaluation DNA absorption Dilution 1000 mg/L 3 0 0 0 5 results ratio B₁₀series  100 mg/L 8 0 0 0 8 (%) after 10  10 mg/L 14 0.2 0 0 18 containertransfers Comparative Comparative Example 3 Example 4 Example 5 Example6 Example 4 Resin Cycloolefinic Types Hydrogenated HydrogenatedHydrogenated Hydrogenated Hydrogenated composition polymer product B ofproduct B of product B of product B of product B of ring-openedring-opened ring-opened ring-opened ring-opened polymer of polymer ofpolymer of polymer of polymer of cycloolefins cycloolefins cycloolefinscycloolefins cycloolefins Production method Production ProductionProduction Production Production Example 2 Example 2 Example 2 Example 2Example 2 Glass-transition 102 102 102 102 102 temperature (° C.)Content 100 100 100 100 100 (parts by mass) Antioxidant Content 0 0.010.1 0.48 0.72 (parts by mass) Biochemical tool (Eppendorf tube Contactangle of 81 91 92 89 84 container) contacting part to water (°)Evaluation DNA absorption Dilution 1000 mg/L 4 0 0 0 7 results ratio B₁₀series  100 mg/L 10 0 0 0 12 (%) after 10  10 mg/L 18 0.4 0 0 20container transfers

TABLE 2 Comparative Comparative Comparative Example 5 Example 7 Example8 Example 9 Example 6 Example 7 Example 10 Resin Cycloolefinic TypesHydro- Hydro- Hydro- Hydro- Hydro- Copolymer Copolymer compositionpolymer genated genated genated genated genated D of cyclo- D of cyclo-product product product product product olefin olefin C of ring- C ofring- C of ring- C of ring- C of ring- and chain and chain opened openedopened opened opened olefin olefin polymer polymer polymer polymerpolymer of cyclo- of cyclo- of cyclo- of cyclo- of cyclo- olefinsolefins olefins olefins olefins Production method Production ProductionProduction Production Production Production Production Example 3 Example3 Example 3 Example 3 Example 3 Example 4 Example 4 Glass-transition 6868 68 68 68 138 138 temperature (° C.) Content 100 100 100 100 100 100100 (parts by mass) Antioxidant Content 0 0.01 0.1 0.49 0.73 0 0.01(parts by mass) Biochemical tool (Eppendorf Contact angle of 80 91 91 8882 72 89 tube container) contacting part to water (°) Evaluation DNADilution 1000 mg/L 5 0 0 0 8 5 0 results absorption series  100 mg/L 110 0 0 15 8 0 ratio B₁₀ (%)  10 mg/L 22 0.5 0 0 25 15 0.3 after 10container transfers Comparative Comparative Comparative Example 11Example 12 Example 8 Example 9 Example 10 Resin Cycloolefinic TypesCopolymer Copolymer Copolymer Poly- Poly- composition polymer D ofcyclo- D of cyclo- D of cyclo- propylene propylene olefin olefin olefinand chain and chain and chain olefin olefin olefin Production methodProduction Production Production — — Example 4 Example 4 Example 4Glass-transition 138 138 138 — — temperature (° C.) Content 100 100 100100 — (parts by mass) Antioxidant Content 0.09 0.45 0.75 — — (parts bymass) Biochemical tool (Eppendorf Contact angle of 90 87 80 103 100 tubecontainer) contacting part to water (°) Evaluation DNA Dilution 1000mg/L 0 0 5  0 6 results absorption series  100 mg/L 0 0 10  80 60 ratioB₁₀ (%)  10 mg/L 0 0 18 100 98 after 10 container transfers

From Tables 1 and 2 and FIG. 1, it is understood that absorptions of thebiochemical substance at the surfaces contacting the samples of thebiochemical substance were reduced satisfactorily even at lowconcentrations of the biochemical substance, in Examples 1 to 12employing the biochemical tools (containers) each having a partconfigured to contact the samples of the biochemical substance was madeof a resin composition containing certain cycloolefin polymers and theantioxidant in a certain amount.

On the other hand, it is understood that the biochemical tools(containers) of Comparative Examples 1 to 8 in which the contents of theantioxidant in the resin compositions were out of the predeterminedrange were inferior in their capability to reduce absorption of thebiochemical substance to the surfaces contacting the samples of thebiochemical substance.

Further, it is also understood that the biochemical tools (containers)of Comparative Examples 9 and 10 in which the resin compositions did notcontain a certain cycloolefin polymer were remarkably inferior in theircapability to reduce absorption of the biochemical substance to thesurfaces contacting the samples of the biochemical substance.

INDUSTRIAL APPLICABILITY

According to the present disclosure, a biochemical tool is providedwhich can satisfactorily reduce absorption of a biochemical substance toa surface contacting a sample of the biochemical substance.

1. A biochemical tool configured to contact a sample of a biochemicalsubstance, comprising: a part configured to contact the sample of thebiochemical substance, the part being made of a resin compositioncontaining at least one cycloolefin polymer selected from the groupconsisting of a copolymer of a cycloolefin and a chain olefin, aring-opened polymer of a cycloolefin, and a hydrogenated product of aring-opened polymer of a cycloolefin, and an antioxidant, the resincomposition comprising 0.01 parts by mass or more and 0.7 parts by massor less of the antioxidant relative to 100 parts by mass of thecycloolefin polymer.
 2. The biochemical tool according to claim 1,wherein the antioxidant comprises a hindered phenolic antioxidant. 3.The biochemical tool according to claim 1, wherein the contact angle towater of the part configured to contact the sample of the biochemicalsubstance is 85° or more.